Nowadays, many areas employ floor-heating systems to increase room temperature. In the floor heating system, floor-heating pipes are laid under the floor so as to radiate heat in the room. At present, in prior art, the heating water is flowing in the floor heating pipe, that is, the heating water enters through the inlet and then flows out from the outlet of the floor heating pipe. When the floor heating pipe is fabricated, the temperature of the inside water is about 80° C. There are varieties of metal impurities and non-metal impurities mixed in the water. The metal impurities can seriously abrade the floor heating apparatus. The usage life of the floor heating apparatus can be extended by the usage of filter. Most existing filters can only remove metal impurities, but cannot remove non-metal impurities effectively. The impurities left inside the filter have accumulated more and more over time that can easily block the filter and influence the heating effect of the floor heating system. The disassembling of the filter and the replacement of the filter cartridge should be performed by professional service personnel, which is not only inconvenient, but also increases the maintenance cost.